How to handle redirects properly in Traefik

I'm trying to reverse proxy a VMware Virtual Center appliance.

  http:
    routers:
      to-vmwarevc:
        entryPoints:
        - websecure
        rule: "Host(`vmwarevc.hostname.com`)"
        tls: {}
        service: vmwarevc-service
    services:
      vmwarevc-service:
        loadBalancer:
          passHostHeader:
          servers:
          - url: https://internalvc.domain.local

After landing on the initial page, i choose for the html client.
after that i get redirected to https://vmwarevc.hostname.com/ui/login

I get redirected to https://internalvc. domain.local /websso/SAML2/SSO/vsphere.local?SAMLRequest=zVRdb9owFH3fr4j(somereallylonghash) instead of the proxied URL

Request header

Host: vmwarevc.hostname.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.9) Gecko/20100101 Goanna/4.4 Firefox/68.9 PaleMoon/28.8.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Referer: https://vmwarevc.hostname.com/ui/
Cookie: <redacted>
Connection: keep-alive

Response Header

HTTP/2.0 302 Found
X-Firefox-Spdy: h2
cache-control: no-store
content-length: 0
date: Tue, 31 Dec 2019 08:28:47 GMT
location: https://virtualcenter.domain.local/websso/SAML2/SSO/vsphere.local?SAMLRequest=zVRdb9owFH3fr4j(somereallylonghash)
pragma: no-cache
server: Anonymous
strict-transport-security: max-age=30758400; includeSubDomains
x-frame-options: deny

Version: 2.1.1
Codename: cantal
Go version: go1.13.5
Built: 2019-12-12T19:01:37Z
OS/Arch: linux/amd64